Use network's connectTo when available.

Author: scott-fleischman

Database/MongoDB/Internal/Network.hs

@@ -3,19 +3,38 @@
 
 module Database.MongoDB.Internal.Network (PortID(..), N.HostName, connectTo) where
 
-import Control.Exception (bracketOnError)
-import Network.BSD as BSD
-import System.IO (Handle, IOMode(ReadWriteMode))
 
 #if !MIN_VERSION_network(2, 8, 0)
+
 import qualified Network as N
+import System.IO (Handle)
+
 #else
+
+import Control.Exception (bracketOnError)
+import Network.BSD as BSD
 import qualified Network.Socket as N
+import System.IO (Handle, IOMode(ReadWriteMode))
+
 #endif
 
+
+-- | Wraps network's 'PortNumber'
+-- Used to easy compatibility between older and newer network versions.
 newtype PortID = PortNumber N.PortNumber deriving (Show, Eq, Ord)
 
--- Taken from network 2.8's connectTo
+
+#if !MIN_VERSION_network(2, 8, 0)
+
+-- Unwrap our newtype and use network's PortID and connectTo
+connectTo :: N.HostName         -- Hostname
+          -> PortID             -- Port Identifier
+          -> IO Handle          -- Connected Socket
+connectTo hostname (PortNumber port) = N.connectTo hostname (N.PortNumber port)
+
+#else
+
+-- Copied implementation from network 2.8's 'connectTo', but using our 'PortID' newtype.
 -- https://github.com/haskell/network/blob/e73f0b96c9da924fe83f3c73488f7e69f712755f/Network.hs#L120-L129
 connectTo :: N.HostName         -- Hostname
           -> PortID             -- Port Identifier
@@ -30,3 +49,4 @@ connectTo hostname (PortNumber port) = do
           N.connect sock (N.SockAddrInet port (hostAddress he))
           N.socketToHandle sock ReadWriteMode
         )
+#endif